Calling all odd-rocketeers, IT'S MILLER TIME!

[The Astronaut Farmer]

I'm designing an odd-roc right now, and was looking into what I should use for clear fins. McMaster-Carr's description made it sound like Lexan would work for mine, I'm planning on using a 54 mm MMT and perhaps a 1526K160-6 by CTI (longburn motor due to the nature of the rocket). I can PM you if you think this is too off topic, I plan on making a topic about my rocket but I wanted to finish up the CAD model so I can better explain it. But is Lexan an appropriate clear material for a rocket of that size or should I be looking at a different polycarbonite?

[chadrog]

As far as I know, polycarbonate is polycarbonate - Lexan is just a brand. There are three different "grades", but I don't think any one of them is a better option for our purposes. My fins are not Lexan proper, just the brand of polycarbonate that my local Grainger sells. I've heard it's the way to go because it won't shatter, I'm no expert on the subject by any means. For your project, I'd definately go with something thicker than mine, possibly even laminate them. I think a lot has to do with the profile and area of the fin as well. What kind of shape are you working with? Mine are pretty floppy due to the shape, but I'm not going to be flying high impulse motors either. I'd like to see what you're working on when you get it going, I can probably learn a thing or two too.

[The Astronaut Farmer]

Okay thanks, that clears it up a bit. Yeah definitely thicker will be needed! I'll save the rest of the discussion for when I post the thread, I am learning how to use new CAD software, once I figure it out I'll get a thread up in this forum. Nice looking rocket by the way! Did you say earlier when you plan on launching it?

[chadrog]

I look forward to your build. Thanks for the compliment - the maiden flight was to be this coming Saturday the 28Th, but our region is experiencing a nasty drought period that has suspended all of our flying until further notice, boo.

[Salvage-1]

I love the foam top on it! The color of the foam actually looks like real beer foam!

Cant wait to see it fly. Remember the Oddroc rule, "stick the largest av impulse motor in it, coz it its gonna go wrong, you want it far away when it happens!"

[SMR]

I'm designing an odd-roc right now, and was looking into what I should use for clear fins. McMaster-Carr's description made it sound like Lexan would work for mine, I'm planning on using a 54 mm MMT and perhaps a 1526K160-6 by CTI (longburn motor due to the nature of the rocket). I can PM you if you think this is too off topic, I plan on making a topic about my rocket but I wanted to finish up the CAD model so I can better explain it. But is Lexan an appropriate clear material for a rocket of that size or should I be looking at a different polycarbonite?

Lexan is the GE trademark brand name of Polycarbonate. Any Polycarbonate will do. Be careful not to get Acrylic (trade name Plexiglas), which is sometimes sold in the same hardware stores, side-by-side with Polycarbonate. Acrylic is less likely to scratch but more likely to chip or shatter than Polycarbonate. Downsides to Polycarbonate is it is more expensive, more bendable (flutter) at normal temperatures, and yellows over time due to ultraviolet rays.

[chadrog]

The nose-cone-ish component starts with some crappy 1/2" ply. Two disks are made, then sandwiched together with a tee-nut locked into a counterbore between the two. Tee-nut will serve as attachment of shock cord, and a solid attachment point of a copious amount of nose weight. The protruding wood screws hold the disks together, and give the foam something to hold on to.

[chadrog]

I then tapered the top foam area of the bottle to use as the mold for the nose foam. The cavity was lined with tape to keep everything separate. Had the whole process of this down before I started, with one issue - the last step requires a balloon, and I overlooked the possibility of the foam attacking it. Did a little test, with favorable results. The thought of a piece of latex (under tension) covered with that goo letting loose made me chuckle, as long as it didn't happen to me...

[chadrog]

I then started filling the cavity with small amounts of foam, until it was about a half inch from the top.

[chadrog]

When the first foam layers were dry, I popped the slug out. Oops, forgot to take a picture.
At this point, the balloon comes into play.

The base section is worked into the balloon.

The first balloon breaks, but then you know how to do it...

Slug is then fit back into the top of the bottle, and balloon is stretched over the outer part of the foam. This will allow the cone/plug foam to hopefully overlap a bit without adhearing.

[Salvage-1]

Loving this thread!! You have so many neat ideas!

Now... working on this idea.. Champagne bottle with a cork popping at apogee.

[chadrog]

Loving this thread!! You have so many neat ideas!

Now... working on this idea.. Champagne bottle with a cork popping at apogee.

Thank you. Got a line on the bubbly bottles? I'd consider a fleet.YEE-HAA!!!

[chadrog]

It didn't turn out exactly as I'd hoped, but what does? Good nuff for guessing, I guess. The volume of foam I mixed for the final foam "cap" was a bit too small, but close enough. You can call it what you like, I'm calling it a nose cone.

[chadrog]

Millertime had it's first and last flight yesterday, sad to report. The up part was great, strait and true even with twelve-ish MPH winds. I thought the Aerotech "Medium" delay would be ok, guess it was a bit too long...
My son made an attempt at filming the flight, bless his heart for trying. Liftoff and in-flight photos by SMR, thanks Sather.

[Daddyisabar]

That's what I call Livin' the High Life!

[cwbullet]

very neat idea. I did on with a Gatoraid bottle. I alse make a V2 out of Gatoraid bottles. I called it the G2-V2